The present invention relates to dental amalgamators of the type which rapidly vibrate a capsule containing an amalgam mixture, so as to thoroughly mix the ingredients. The object of the invention is to provide an amalgamator in which the mercury vapors given off during amalgamation are largely prevented from entering the air in the neighbourhood of the amalgamator.
The high speed mixing of dental amalgams which is achieved in present day amalgamators, along with the attendant rises in temperature, produce mercury vapors which usually enter the air around an amalgamator, and which can cause quite high levels of mercury in this air. In fact, tests in the vicinity of present day amalgamators show that there is frequently a concentration of mercury three or more times higher than the normally acceptable limits for health.
It has been proposed to remove the mercury vapor from the air in places such as dentists surgeries by use of an extraction fan and filter, such arrangement being shown in U.S. Pat. No. 3,956,458 which issued May 11, 1976 to Anderson. Such an arrangement however does not prevent an operator from breathing in mercury vapors when he or she is near to the amalgamator.
Also, efforts have been made to produce a completely leak-proof capsule which does not give off any vapor during amaglamation. However, the fact that such a capsule is leak-proof ensures that a pressure of mercury vapor is built up in the capsule during the amalgamation due to heat generated during mixing, so that a substantial amount of the mercury vapor is still released when the capsule is opened.
The present invention provides an amalgamator in which the amount of mercury vapor which can enter the air surrounding the amalgamator is very substantially reduced.
In accordance with one aspect of the invention, a dental amalgamator comprises a casing carrying a capsule holder and drive means therefor, a lid movable from an open position allowing access to the capsule holder to a closed position in which it cooperates with the casing to form an enclosure for a capsule held by the holder, and in which the enclosure has air inlet means allowing air to flow from the atmosphere into the enclosure. The enclosure communicates with an outlet adapted for connection to a vacuum source, whereby during amalgamation air may be drawn by the vacuum source into the enclosure, the air being mixed with mercury vapors within the enclosure and then being drawn through the outlet into the vacuum source. With this arrangement, the air which flows into the enclosure during amalgamation, being drawn by the vacuum source, purges the mercury vapor from the enclosure during amalgamation. Preferably, the flow of air is continued sometime after amalgamation has ceased, for most effective removal of mercury vapors.
The amalgamator described above may be attached to a remote source of vacuum, such as an exhaust fan. However, in the preferred embodiment of the invention, self contained apparatus is provided which comprises a casing carrying a capsule holder and drive means therefor, a lid movable from an open position allowing access to the capsule holder to a closed position in which it cooperates with the casing to form an enclosure for a capsule held by the holder, the enclosure having air inlet means allowing air to flow from the atmosphere into the enclosure, and the apparatus further comprises a vacuum pump arranged to communicate with the enclosure via a mercury filter medium.